GTHTR300 cost reduction through design upgrade and cogeneration

Japan Atomic Energy Agency began design and development of the Gas Turbine High Temperature Reactor of 300MWe nominal output (GTHTR300) in 2001. The reactor baseline design completed three years later was based on 850 °C core outlet temperature and a direct cycle gas turbine balance of plant. It attained 45.6% net power generation efficiency and 3.5 US¢/kW h cost of electricity. The cost was estimated 20% lower than LWR. The latest design upgrade has incorporated several major technological advances made in the past ten years to both reactor and balance of plant. As described in this paper, these advances have enabled raising the design basis reactor core outlet temperature to 950 °C and increasing power generating efficiency by nearly 5% point. Further implementation of seawater desalination cogeneration is made through employing a newly-proposed multi-stage flash process. Through efficient waste heat recovery of the reactor gas turbine power conversion cycle, a large cost credit is obtained against the conventionally produced water prices. Together, the design upgrade and the cogeneration are shown to reduce the GTHTR300 cost of electricity to under 2.7 US¢/kW h.